Packaging method



Aug. 7, 1934.

R. L. CHURCHILL PACKAGING METHOD Filed Jan. 16, 1933 gwuzntoz:

' Patented Aug. 7, 1934 PACKAGING METHOD Robert L. Churchill, Kingsport,Term., assigner te Eastman Kodak Company, Rochester, N. Y., acorporation of New York Application January 16, 1933, vSerial No.652,017

8Claims.

'I'his invention relates to the art of packaging and more particularlyto a meth'od whereby various types of wrappings produced from celluloseorganic esters ,may be shrunk upon the article to 5 beprotected in sucha manner as to produce a neat, tight wrap free from wrinkles.

When wrapping various articles of commerce 15 sheeting, it ispractically impossible te draw the Imaterial suillciently tightly aroundthe object to produce a smooth wrap without breaking. It has beenproposed to obviate these diillculties by employing a type of sheetingwhich possesses 0 self-shrinking properties. In 'such'a case the sheetis merely 'wrapped around the article, sealed if desired, and permittedte shrink tightly thereover. One such type. of sheeting is composed ofcellulose acetate containing a substantial pro- 5 portion, say 2li-40%of a4 plasticizer such as diethyl phthalate, having a low boiling pointand higlrvapor pressure, as compared'to other plasticizers, which givesthe sheeting markedly shrinking qualities.

It is the principal object of the present invention to improve upon thepackaging art, especially with reference to the wrapping of various 1articles in thin cellulose organic estersheeting. Another object is toprovide a simple and effective method whereby a tight wrap free fromwrinkles vmay be obtained. A specic object is to provide a method oftightening wrappers of cellulose acetate thin sheeting A after they areapplied tov plished if the article, after wrapping, is sub-f jected tothe action of a solvent or swelling agent for the cellulose organicester material employed and then permitted to dry. I-have found that aneven, uniform shrinkage takes place throughmanner, the edge portions inmany cases being sealed by a suitable sealing agent or cement or simplyby the application of heat and pressure. 'I'he wrapping material at thisstage of the operation is relatively loose and has a tendency to wrinkleor lbuckle due to the uneven tension applied to the sheeting duringapplication to the-article, or in some cases, due to the particular formof the article itself. The wrapped article is next subjected to theaction of a' s'welling agent or a solvent for the material of sheeting.This may be accomplished by moistening or wetting the outer surfaces ofthe wrapper with the agent by brushing or dipping. In some cases it maybe desirable to apply the swelling or solvent agent in vapor form bysuspending the wrapped article in ay closed vessel containing thesaturated vapor or by spraying the swelling or solvent agent thereon.

A typical example of the method according to the invention may becarried out as follows. An article, such as a cake of soap, a can ofpowder, a properlyl stoppered bottle of liquid or other article ofcommerce is suitably wrapped in a thin sheet of cellulose acetate, theedge portions of the wrapper being preferably sealed in any appropriatemanner. A solution containing 67% denatured ethyl alcohol and 33%acetone is then prepared and the outer surface of the wrapper ismoistened or wetted slightly by brushing the solution on with a softbrush. The wetted or moistened surface dries rapidly and mostunexpectedly an almost immediate tightening or shrinking of the wrappertakes place, resulting in a smooth, neat package substantially free fromwrinkles, buckled portions, or other unevenness.

'I'he composition of the shrinking agent may vary'widely.A .It must,however, be either a'solvent or a swelling agent for the particularcellulose ester material dealt with. As a general rule,

swelling agents are to be preferred due to their less drastic action onthe sheeting. When using*- this latter type of agent less manipulativecare is required in application than with an agent which has apronounced solvent action. When4 working with 'relatively thickmaterials it may in` some cases be necessry,-ither to employ a solventout the sheeting, which shrinkage has the enect alone, or a mixture ofsolvent and swelling agent.

of tightening the wrapper on the article and smoothing out wrinklesinamanner impossible when working by hand or even with the most per. j feetmechanical packaging equipment.4

'The method is extremely' simple and may'be carried out in a number ofdiil'erent ways. The article to becovered is first wrapped'in cellulose55 acetate thin sheeting, for examplain the desired It will be apparentthat the optimum proportions of solvent and' swelling agent willnecessarily be determined with reference to the type of material dealtwith, its thickness, and other properties.

In no case, howevfenlwill the agent be sulciently drastic in its actionto apprecably; eat into or through the surface 'of the sheeting.

In the case of cellulose acetate sheeting, for

looA

somewhat loosely.

may be by simply brushing it onto the surface .of

the wrapper and permitting it to evaporate at room temperature. In somecases the wrapped article may even be dipped momentarily in a body ofthe liquid and then permitted to dry, or the article may be suspendedfor a short time in a closed space containing the saturated vapors ofthe liquid.

The two gures of the drawing graphically illustrate the eilectivetightening of a wrapper on an article of irregular shape, by means of myinvention In Fig. 1 the numeral 1 indicates a properly stoppered bottleof liquid which has been relatively loosely wrapped in a thin,transparent sheet of cellulose acetate wrapping material (2) and sealedby means, of solvent sealing agents or merely by application of heat andpressure. It will be noted that .the material, even in spite of the mostcareful attention to wrapping, wrinkles andbuckles and accordinglytsaround the bottle Fig. 2 illustrates the same package after therelatively loosely ttin'g wrapper has been treated by application of aagent such as described above. The wrapper (2) is now drawn tightlyaroundthe bottleand the wrinkles are 'cellulose acetate propionate,cellulose completely smoothed out giving the package an extremely neatattractiveappearance.

While I have described my invention with particular reference tocellulose acetate sheeting, it is equally ,applicable to methods ofpackaging involving the use of other types of single or mixed celluloseorganic ester material, such as cellulose propionate, cellulosebutyrate, cellulose stearate, acetate butyrate and the like.

It will also be apparent that a wide latitude is permitted in theproportions of the various ingredients making up the shrinking bath orliquid. While I have described a bath containing approximately 67% ofnon-solvent (alcohol) to 33% of solvent (acetone), I may employ as muchas non-solvent, or more, with a correspondingly less amount of solvent,or even no solvent, if desired.

The matter of proportions o f any given combination of ingredients willalso begoverned largely by the particular type of sheeting dealt with.

The method of the presentV invention has many advantages' over knownmethods of securing tightly fitting wrappingson package goods. Even themost eicient mechanical means of wrapping goods does not permit the sureand effective tightening of the wrappermade possible by thehereindescribed method. No complicated machinery or involvedmanipulative procedure-is required, the method being particularlycharacterized by its extreme simplicity. l

As many apparently widely diiferent embodiments of this invention may bemade without departing from the spirit and scope thereof, it istobeunderstoodthatIdo notlimitmyselftothe therefrom.

agent for the ester which upon evaporation tautens the wrapper.

\2. The method 'of packaging which comprises enclosing an article in awrapper comprising a non-self-shrinking sheetof cellulose organic estermaterial free from water soluble compounds without tautening andapplying an organic -swelling agent for the ester to the outer surfaceof the wrapper which upon evaporation tautens the material, andpermitting the agent to evaporate -3. The method of packing whichcomprises enclosing an article in a wrapper comprising anon-self-shrinking sheet of cellulose organic ester material free fromwater soluble compounds Without tautening and applying to the outersurface of the wrapper, a solution comprising an organic swelling agentfor the cellulose organic ester and a solvent for said ester therefor,and permitting the solution to evaporate, whereby the wrapper isuniformly shrunk and tautened around the article.

4.' The method of packaging which comprises enclosing an article in awrapper comprising an organic sheet of cellulose acetate, applying tothe outer surface of the wrapper an organic swelling agent for thecellulose acetate, and permitting the agent to evaporate therefrom,whereby the cellulose acetate is uniformly shrunk and tautened aroundthe article.

5. The method of packaging which comprises enclosing an article in awrapper comprising a sheet of cellulose acetate without tautening,applying to the outer surface of the wrapper an agent comprising 67%alcohol and 33% acetone, and permitting the agent to evaporatetherefrom, whereby the cellulose acetate is uniformly shrunk andtautened around the article.

6. The method of packaging which comprises enclosing an article in awrapper comprising a non-self-shrinking sheet of cellulose organic estermaterial free from water-soluble compounds, without tautening, andsubjecting the-wrapper to the action of a liquid which consists of amixture of an organic non-solvent swelling agent for the celluloseorganic ester and a solvent therefor. y

'1. Themethod of packaging which comprisesenclosing an article in awrapper comprising a non-self-shrinking sheet of cellulose acetate freefrom water-soluble compounds, without tautening, and subjecting thewrapper to the action of a liquid which consists of a mixture of anorganic non-solvent swelling agent for cellulose acetate and a solventtherefor.

8. The method of packaging which comprises enclosing an article in awrapper comprising a nonself-shrinking sheet of cellulose acetate freefrom watersoluble compounds, without tautening, 'and subjecting thewrapper to the action of a liquid which contains a major portion of fanorganic non-solvent swelling agent for the cellu-z lose.acetate Vand asolvent therefor` ROBERT L. CHURCHILL.'

